1. Field of the Invention:
The present invention relates generally to surgical instruments and, more particularly, to surgical retractors for drawing and holding soft tissue away from the operative field during a surgical procedure.
2. Description of the Prior Art:
In surgical procedures, it is necessary to hold the edges of an incision apart to provide a clear operating field within which the surgeon can operate. Retractor devices for this purpose have long been used but have typically required one or more surgical attendants on a continuous basis to either hold them or closely monitor their function. One construction known to the prior art is presented in U.S. Pat. No. 3,749,088 to Kohlman. This patent discloses retractor apparatus which overlies the operative field and utilizes a plurality of opposed retractor units. The retractor units are adjustably mounted on a frame and act together to engage the tissue at the edges of the incision to draw it away from the operative field and expose it for an ensuing surgical procedure.
In a similar manner, U.S. Pat. No. 3,364,919 to Hunnicutt overlies the operative field and uses an elongated rectangular sheet metal strap of a chosen size and contour for engaging the edge of the incision.
A retractor of specialized design, intended specifically, for a gall bladder operation, is disclosed in U.S. Pat. No. 2,863,444 to Winsten. In this instance, the retractor is required to be held continuously by hand during surgery to draw the patient's liver away from the operative field.
None of the foregoing patents discloses a construction which is intended for, or renders possible, either temporary or permanent fixation to an underlying bone. While some previously known constructions of retractors were intended to engage an underlying bone, they were not temporarily or semi-permanently affixed to the bone. One instance is disclosed in U.S. Pat. No. 4,610,243 to Ray. In this instance, a retractor is provided which is said to be particularly useful for spinal surgery and comprises a malleable metal band one end of which is formed with rigid metal spikes intended for engagement with the underlying bone. The spikes do not appreciably penetrate the bone, only to the extent to provide a fulcrum enabling the band to engage the edge of the incision and draw back the soft tissue away from the operative field when a weight is applied to an opposite hooked end of the band.
Also known is U.S. Pat. No. 4,686,972 to Kurland which is a combination retractor and guide for a boring tool. An elongated main body has one end serrated for engagement with the bone to be drilled. The other end of the retractor is apertured for reception of the fingers of a surgical attendant and must be held throughout the drilling procedure to deflect any tissue which would otherwise interfere with the process.
While the patents to Ray and Kurland disclose retractors which are engageable with a bone, they do not provide for temporarily, but immovably, mounting the retractor to the bone. In each instance, which is typical of the prior art, the retractor must be held by a surgical attendant during the entire course of the surgical procedure requiring its use.
Thus, a significant drawback of the prior art resides in the need for surgical attendants in the operating room to substantially continuously hold, or closely monitor the use of, a surgical retractor.